Retardation device



Sept. 16} 1924.. 150mm T. T. GREENWOOD RETARDATION DEVICE Filed May 5. 1920 i :11 D s TALMA T. GREENWOOD, OF'TEMPLETON, MASSACHUSETTS, ASSIGNOR, BY MES NE AS- SIGNMENTS, TO CONDIT ELECTRICAL MANUFACTURING COMPANY, A CORPORA- TION OF MASSACHUSETTS.

RETARDATION DEVICE.

Application filed May 5, 1920. Serial No. 379,158.

To all whom it may concern.

Be it known that I, TALMA T. GREENWOOD, a citizen of the United States, residing at Templeton, in the county of Worcester and State of Massachusetts, have invented an Improvement in Retardation Devices, of which the following is a specification.

This invention relates to retardation devices adapted to control the opening of an electric circuit by an electric switch and has especial reference to the type of device having a cylinder adapted to contain a fluid with an electrically actuated piston operable therein.

The object of the invention is to provide an improved retardation device and one having means whereby the retarding effect is a minimum at the start of its operation and increases as the actuating effect is increased.

Fig. 1 is a sectional elevation'of a re tardation device embodying my invention in its normal or unactuated condition,

Fig. 2 is a sectional elevation of the retarding device in an actuated condition,

Figs. 3 and 4 are sectional views for modifications of the invention,

Fig. 5 is a section along lines 33 of Fig. 1.

As here shown, the device is immersed in the oil contained in the oil receptacle 10.

secured to and depending from the solenoid enclosing casing 11.

In that embodiment of the invention illustrated in Fig. 1, the retardation device includes the cylinder 12 secured to said casing and depending therefrom. A-piston 13 is slidably disposed within said cylinder and is substantially oil tight therein and is connected by the rod 14 to the solenoid core 14' or other piston actuating means. Said cylinder is formed with the end wall 15 having the perforations 16 therethrough preferably adjacent its periphery. The lower end of the cylinder is externally screwthreaded to receive the clamping ring 17 having the inwardly extending flange 18. A. flexible diaphragm 19 of thin material having the central perforation 20 therein is secured to the end of the cylinder by said ring 17 and a spacing ring 21 interposed between the end wall of the cylinder and the diaphragm serves to hold the diaphragm above but closely spaced from the end wall whereby to provide an oil passage 22 connecting the aperture 20, and the perforafluid pressure difference on opposite sides of it, and the perforations 20 and 16 are offset so that the oil must travel along the space 22 between the diaphragm and the end wall. Said diaphragm and end wall of the cylinder constitute valve members controlling the flow of fluid into the cylinder.

When the piston begins to be moved upwardly within its cylinder a pressure difference is set up between the cylinder and the oil in the oil receptacle, thereby causing a flow of oil into the cylinder. This pressure difference acts on said flexible disc or diaphragm 19 and the disc yields or is deflected toward the end wall of the cylinder, thereby restricting the passage 22 and diminishing the rate of flow of oil into the cylinder, and the deflection of the diaphragm and consequent restriction of the fluid flow may be roportional to the actuating force applied to the piston whereby the time period of operation of the device may be the same regardless of the strength of the actuating force. When the actuating means is a solenoid, the initial actuating force may be small, and the retarding effect is correspondingly low whereby the core will be positively moved within the solenoid; and when the core has been moved therein a short distance, the actuating force is increased and the retarding effect is correspondingly and automatically increased.

Prefenably I so arrange the thickness of the spacing ring that the space 22 is about equal to one fourth the diameter of the perforation 20 but this obviously may be altered to accomplish specific performances.

In the modification shown in Fig. 3 the cylinder is open ended and a valve stem 25 is extended through the perforation 20 in the flexible disc 19 and is supported by the arm 26 carried by the clamping ring. The yielding of the flexible diaphragm 19 under a pressure difierence acting thereon serves to throttle the opening 20 thereby to restrict the flow of oil therethrough.

In the modification shown in Fig. 4 the yielding diaphragm is replaced by the yield- '1ng piston slidably arranged in the bore 31 of the cylinder and normally pressed outward by the spring 32. The end wall of said piston has the valve opening 32 therein in which the needle valve 34L carried b the end wall of the cylinder is extend a pressure diflerence acting on said piston serves to move it upward against the action of said spring-32 thereby to throttle the valve opening,

I claim l, A retardation device comprising a cylthereby to govern the flow oi. fluid through the aperture and norm-ally biased away from said valve member, and means to flex said diaphragm comprising means to set up a fluid pressure diflerence on opposite sides of it I 3:. In a retardation device a relatively sta tionary valve member, a relatively movable valve member having an aperture themthrough movable toward and away from said stationary member to govem the flow otfluid through the aperture and means to move said movable valve member comprising means to set up a fluid pressure ditierence A on opposite sides of it,

a neoasei 4i, In a retardation device, a cylinder ha ing a flat end wall with fluid apertures therethrough adjacent the side-wall, a diephragm having an aperture in it out of alient with said other apertures closely spaced from said end' wall flexible toward and away thereifrom to govern the flow fluid through its aperture, and means to flex said diaphragm including a piston operable within said cylinder.

5. In a retarding device, a cylinder lraving a flat end-wall with fluid apertures therethrough adjacent its side-wall, aflexible dim fflflx having a fluid aperture throughout of a guru with said fluid apertur means to secure said diaphragm clo V spaced above the end-wall out said cylinder,

said diaphragm capable of being flexed t ward and away from said end-wall 'th reby to vary the flow of fluid through the aperture therein, and means to set up a pressure diflerenoe etween opposite sides of said diaphragm to flex it including a piston operable within said cylinder. 6. In a retardation device, a cylinder ing an end-wall with fluid a .ertures therethrough adjacent its side-wal a piston operable therein, a flexible diaphragm ha a central fluid \apemure therethrough ov r securing said diaphragm to the cylr r closely spaced above its end-wall adm"ti" of tree fluid communication with the 'ei face of said diaphragm,

In testimony whereof, l have signed name to this specification.

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